Madni Ahmed, 20, repeatedly plunged the large blade into the neck and body of Riasat Bi, 86, as she tried to protect her grandson Faizaan Javed
The smirking killer of grandma Riasat Bi has been jailed for life - after his own father told police his son may have been involved in her murder.
Madni Ahmed, 20, repeatedly knifed the 86-year-old at her home in Small Heath, Birmingham, where he had also stabbed her grandson as he slept.
The killer from Stoke-on-Trent launched the frenzied and motiveless attack after buying knives online using his brother's ID.
He was found guilty of murder, attempted murder, being in possession of an offensive weapon and affray after a trial at Birmingham Crown Court.
He was sentenced to life in prison today, where the judge set a minimum term of 36 years.
Ahmed stabbed Riasat Bi's 18-year-old grandson 15 times as he slept in the front room of the family home, before fatally stabbing Mrs Bi and leaving her with more than 25 injuries on the morning of July 12.
He then continued upstairs where he was met by another grandson who ordered him to leave before grabbing a knife in self-defence. Ahmed refused to leave and following a scuffle he received a slash wound to his arm.
The killer fled the house via the attic window, ditching his knife in the roof guttering before jumping into a neighbour's garden.
Ahmed's blood was later found on the fence panels as he stumbled through the garden and into a neighbour's house, grabbing a knife from the kitchen.
He had called a taxi to collect him from The Akers Trust to take him back to a hostel in Newtown.
However, later that evening, Ahmed was arrested at a hospital in Stoke-on-Trent after detectives traced the phone he had been using throughout the day.
The court heard Ahmed's own father had gone to police to say his son could have been involved after hearing about the murder and seeing Whatsapp footage of the killer leaving the scene.
Riasat Bi, 86, pictured, died as she tried to protect her grandson Faizaan Javed from the attack
Speaking after the case, Miss Bi's daughter - who asked not to be named - told how the tragedy had 'devastated' the close-knit family.
She said: 'My mom had three children and six
